Sheets of material are often used in various industries and in a variety of ways. These materials can include paper, plastic, and other materials manufactured or processed in webs or sheets, such as long sheets of paper collected in reels. The processing of these materials can include printing text, images, and other content on a sheet of paper or other material. These sheets of material are often manufactured or processed at a high rate of speed, such as up to thirty meters per second or more.
It is often necessary or desirable to measure one or more characteristics of a sheet of material as the sheet is being manufactured or processed. For example, in a paper sheet-making process, it is often desirable to measure the color of the paper sheet to verify whether the sheet has a color that is within specification. As another example, in a printing process, it is often desirable to measure the color of the printing on a sheet to verify whether the printed color is within specification.